Development of Loop-Mediated Isothermal Amplification Assays for the Rapid and Accurate Diagnosis of Exserohilum turcicum for Field Applications.

Northern corn leaf blight (NCLB), caused by Exserohilum turcicum, is one of the most devastating foliar diseases of maize. Rapid and accurate diagnosis for this disease is urgently needed but still limited. Here, we establish a field-deployable diagnostic method to detect E. turcicum based on loop-mediated isothermal amplification (LAMP) assays. A software application called K-mer Elimination by Cross-reference was used to search for the specific sequences belonging to E. turcicum by comparing the whole genome sequence between E. turcicum and other known maize pathogens. Five LAMP primer sets were designed based on specific and single-copy fragments of E. turcicum. Post-LAMP analyses indicated that only the primer set, Et9468_set1, was the most suitable, producing a ladder-like amplification pattern in the agarose gel electrophoresis and a strong fluorescence signal in the presence of SYBR Green I. The LAMP assay using Et9468_set1 primers demonstrated a high level of specificity in distinguishing E. turcicum from six other common fungal pathogens of maize, as well as 12 more fungal and oomycete strains including the epiphytic fungi from maize leaves and other crop pathogens. Moreover, it exhibited remarkable sensitivity by detecting five copies per reaction, which was approximately 104 times more sensitive compared with conventional PCR. The LAMP assay successfully detected E. turcicum in field maize leaves without DNA extraction, demonstrating its suitability for rapid on-spot detection of NCLB. Our study provides a direct LAMP diagnostic method to detect E. turcicum, which enables on-site pathogen detection in the field and the development of preventive strategies for NCLB management.

A harmful MYH11 variant detected in a family with thoracic aortic dissection and patent ductus arteriosus.

Thoracic aortic dissection (TAD) is an important cause of sudden cardiac death and is characterized by high morbidity, mortality, and a poor prognosis. Patent ductus arteriosus (PDA) is a common congenital heart disease. The pathogenesis of both TAD and PDA has been reported to be related to genetic factors. The MYH11 gene, which encodes myosin heavy chain 11, has been reported in individuals with both TAD and PDA. Herein, we first detected a harmful MYH11 missense variant (c. T3728C, p. L1243P) in a TAD and PDA family. This missense variant co-segregated with the TAD/PDA phenotype in this family of four individuals, providing evidence of its harmfulness. Histopathological examinations revealed the presence of fragmented, broken, and lessened elastic fibers and the deposition of proteoglycans in the median of aortic dissection. Moreover, the immunofluorescence results showed that the labeled MYH11 protein in the tissue of the aortic dissection was weaker than that in the normal aorta. We present this familial case to stress the necessity of postmortem genetic testing in such cases among forensic practices. Identifying those culprit gene variants can direct effective genetic counseling and personalized health management in family members (especially first-degree relatives) with high-risk genotypes.

Genome-Wide Association Study of Body Conformation Traits in Tashi Goats (Capra hircus).

Identifying genetic markers of economically valuable traits has practical benefits for the meat goat industry. To better understand the genomic variations influencing body conformation traits, a genome-wide association study was performed on Tashi goats, an indigenous Chinese goat breed. A total of 155 Tashi goats were phenotyped for eight body conformation traits: body height, body length, chest depth, chest width, chest girth, rump width, rump height, and cannon bone circumference. Then, 100 Tashi goats were randomly selected for whole-genome sequencing and genotyped. We obtained 1676.4 Gb of raw data with an average sequencing depth of 6.2X. Clean reads were aligned to the ARS1.2 reference genome, and 11,257,923 single nucleotide polymorphisms (SNPs) were identified. The structure analysis showed that these Tashi goats were almost not genetically related. The 109, 20, 52, 14, 62, 51, 70, and 7 SNPs were significantly associated with body height, body length, chest depth, chest width, chest girth, rump width, rump height, and cannon bone circumference. Within the ±500 kb region of significant SNPs, 183 genes were annotated. The most significantly enriched KEGG pathway was "olfactory transduction", and the most significantly enriched gene ontology (GO) terms were "cellular process", "cellular anatomical entity", and "molecular transducer activity". Interestingly, we found several SNPs on chromosomes 10 and 11 that have been identified multiple times for all eight body conformation traits located in two fragments (114 kb and 1.03 Mb). In chr.10:25988403-26102739, the six SNPs were tightly linked, the TACTAG genotype was the highest at 91.8%, and the FNTB (Farnesyltransferase, CAAX Box Beta) and CHURC1 (Churchill Domain Containing 1) genes were located. In chr.11:88216493-89250659, ten SNPs were identified with several dependent linkage disequilibrium (LD) blocks, and seven related genes were annotated, but no significant SNP was located in them. Our results provide valuable biological information for improving growth performance with practical applications for genomic selection in goats.

[Effects of nitric oxide on the oocyte and embryo development in mice].

OBJECTIVE: To evaluate the effects of exogenous nitric oxide on mouse oocyte maturation in vivo, in vitro fertilization and embryo development. METHODS: By intraperitoneal injection, the experimented female mice were administered separately with sodium nitroprusside (SNP) of dosages at 1.0 mg/kg, 5.0 mg/kg and 10.0 mg/kg when stayed in period of superovulation,and at the same time, the control mice were administered with equal volume of saline solution. At 15 hours after injected intraperitoneally with hCG, the mice were killed by cervical dislocation, of which the oocytes in the oviducts were collected for in vitro fertilization, and also the oocyte maturation, the embryo development and morphological change were observed. RESULTS: (1) In 5.0 mg/kg SNP group, the rates of MI and MII oocytes with no fertilization were higher than those in the control group and 1.0 mg/kg SNP group (P < 0.05, P < 0.01),but the fertilization rate of oocytes was lower in 5.0 mg/kg SNP group than in the control group and 1.0 mg/kg SNP group (P < .01), all mice in 10.0 mg/kg of SNP group died of 20 minutes after administration. (2) The cleavage rate of embryos after 2-cell stage was lower in 5.0 mg/kg SNP group when compared separately with that in the control group and 1.0 mg/kg SNP group (P < 0.01), none of the embryos developed to blastocyst stage in 5.0 mg/kg SNP group. (3) The rate of the fragment formation in embryos during progress was higher in 5.0 mg/kg SNP group than in the control group and 1.0 mg/kg SNP group (P < 0.01). CONCLUSION: The higher concentration of nitric oxide inhibits oocyte maturation in vivo, in vitro fertilization and embryo development,and affects the embryo quality.

Scanning of selection signature provides a glimpse into important economic traits in goats (Capra hircus).

Goats (Capra hircus) are one of the oldest livestock domesticated species, and have been used for their milk, meat, hair and skins over much of the world. Detection of selection footprints in genomic regions can provide potential insights for understanding the genetic mechanism of specific phenotypic traits and better guide in animal breeding. The study presented here has generated 192.747G raw data and identified more than 5.03 million single-nucleotide polymorphisms (SNPs) and 334,151 Indels (insertions and deletions). In addition, we identified 155 and 294 candidate regions harboring 86 and 97 genes based on allele frequency differences in Dazu black goats (DBG) and Inner Mongolia cashmere goats (IMCG), respectively. Populations differentiation reflected by Fst values detected 368 putative selective sweep regions including 164 genes. The top 1% regions of both low heterozygosity and high genetic differentiation contained 239 (135 genes) and 176 (106 genes) candidate regions in DBG and IMCG, respectively. These genes were related to reproductive and productive traits, such as "neurohypophyseal hormone activity" and "adipocytokine signaling pathway". These findings may be conducive to molecular breeding and the long-term preservation of the valuable genetic resources for this species.